Ultrasonic welding is an industrial technique whereby high-frequency ultrasonic acoustic vibrations are locally applied to workpieces being held together under pressure to create a fusion weld. This technique is commonly used for joining similar and dissimilar plastics. The technique is used in industries such as automotive, appliance, electronic, packaging, textile, and medical, among others.
During ultrasonic welding, alignment and leveling of a welding fixture, a welding horn, and the workpieces are important. As an example, when the welding horn is not positioned generally perpendicular to a workpiece, discrepancies in the weld may occur, such as under-welding, and non-uniformity of the weld, among others. Warping or deformation within a workpiece can cause the welding horn to be positioned undesirably with respect to a workpiece, e.g., not perpendicular to the workpiece, during joining, causing discrepancies in the weld.
When the warped workpiece is positioned near a second, joining workpiece for joining, an undesired space is present between the warped workpiece and the joining workpiece. The space between the warped workpiece and the joining workpiece can lead to less-than-ideal weld formation as well.